Surgical access apparatus and method

ABSTRACT

A trocar system for providing access across a body wall includes a trocar and an anchor provided in the form of a first helix. The anchor is adapted for placement in an operative position wherein the anchor extends at least partially through the body wall. A second helix formed on the trocar is size and configured to engage the first helix of the anchor so that rotation of the trocar relative to the anchor moves the second helix along the first helix. In this manner, the trocar is drawn into the anchor as it moves into the body wall. A proximal force applied to the anchor resists tenting of the abdominal wall. The anchor also holds the layers of the body wall together thereby resisting peritoneal separation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/383,927, filed May 17, 2006, which is a continuation of U.S. patentapplication Ser. No. 10/379,461, filed Mar. 3, 2003 and issued as U.S.Pat. No. 7,070,586 on Jul. 4, 2006, which is a continuation-in-part ofU.S. patent application Ser. No. 10/346,846 filed Jan. 17, 2003 andissued as U.S. Pat. No. 6,887,194 on May 3, 2005, the disclosures ofwhich are all hereby incorporated by reference as if each is set forthin full herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to surgical access devices and morespecifically to trocars and insufflation devices used in laparoscopicsurgery.

2. Discussion of Related Art

Abdominal inflation is a critical component of Laparoscopic Surgery. Themost common method to achieve inflation, more commonly referred to asinsufflation, is to pass a sharp needle through the abdominal wall andinto the inner abdominal region, and then inject a gas through theneedle and into the region thereby creating an enlarged or balloonedcavity to accommodate a laparoscopic procedure. Unfortunately, insertionof the needle has been required without any visual aid to facilitatelocation of the sharp needlepoint. In order to reduce the probability ofinadvertent penetration of delicate internal organs in this “blind”procedure, the sharp insufflation needle has been provided with aspring-loaded and retractable safety mechanism.

The safety mechanisms associated with most insufflation needles consistof a blunt or rounded member disposed within the lumen of the needle,and biased by a spring to an extended position beyond the needle tip.This spring must be responsive to the insertion pressure duringplacement of the needle but must be capable of immediately movingforward when that pressure is relieved. This is highly mechanical eventand at best, offers a less than optimal arrangement.

In order to make the insertion of sharp needles into the abdominalregion safer, a common practice has developed where the needle isinserted at an angle to the tissue plane. This of course requires thatthe needle traverse a greater distance through the abdominal tissue, sothe maximum angle is always limited by the length of the needle.

Notwithstanding these attempts to reduce the probability and severity ofan adverse consequence, many inadvertent injuries continue to resultfrom the blind insertion of insufflation needles.

SUMMARY OF THE INVENTION

In a preferred embodiment of the present device, a length of hollowtubing, configured as a helix, is provided with a closed and roundeddistal end. At least one distal side opening allows insufflation gas toexit the spiral tube at the distal end. The proximal end of the spiraltube is fitted with a connecting hub and a valve for connection to a gassupply. In operation, the spiral tube is inserted into a small skinincision and subsequently rotated to separate or part abdominal tissueuntil the distal end emerges from the abdominal wall and into theabdominal region. A significant characteristic of the spiral tube isthat its distal tip emerges nearly parallel to the plane of the innersurface of the abdominal wall and the adjacent internal organs. Withthis orientation, the blunt distal end of the device presents no dangerto these delicate internal structures.

In one aspect, a laparoscopic insufflation needle is adapted formovement across an abdominal wall of a patient to insufflate anabdominal region of the patient, the needle comprises an elongate tubehaving an inflation channel extending between a proximal end and adistal end. The tube is adapted at the proximal end for connection to asource of fluid under pressure, and is adapted at its distal end toexpel the fluid under pressure to insufflate the abdominal region of thepatient. An optical element can be disposed at the distal end of theelongate tube to facilitate visualization of the abdominal wall and theabdominal region of the patient.

In another aspect, an insufflation needle is adapted for movement acrossan abdominal wall and into an abdominal region of a patient. The needleincludes an elongate tube for insufflating the abdominal region with afluid under pressure. The tube is configured to provide a mechanicaladvantage when moved across the abdominal wall.

In another aspect, the insufflation needle includes an elongate tube forinsufflating the abdominal region with a fluid under pressure. Theelongate tube at its distal end is angled relative to the proximal endof the tube to produce an exit angle with an interior surface of theabdominal wall. This exit angle is in a range of less than about 40degrees in order to inhibit penetration of interior organs of thepatient.

In another aspect, the elongate tube of the insufflation needle has adistal end with a distal tip that is free of sharp edges to inhibitcutting the abdominal wall during penetration of the abdominal wall, andto inhibit cutting the interior organs following penetration of theabdominal wall.

An associated method for accessing an abdominal region of the patient bycrossing an abdominal wall of the patient, includes the steps ofproviding an insufflation needle in the configuration of a tube, andturning the tube to facilitate the crossing of the abdominal wall withthe insufflation needle.

In another method, an access device is used to create an abdominalcavity in an abdominal region containing interior organs of the patient.The method includes the steps of providing an elongate shaft having anaxis extending between a proximal end and a distal end, and moving theshaft across the abdominal wall to place the distal end of the shaft inthe abdominal region. Following this placement, the elongate shaft canbe pulled to move the abdominal wall away from the interior organs andto create the abdominal cavity around the interior organs in theabdominal region.

In a further aspect, a surgical device is adapted to provide accessacross an abdominal wall and into an abdominal region of a patient. Thedevice includes a trocar with a blunt tip obturator and a cannula. Ashaft with a proximal end and a distal end forms a coil having a coilaxis, the coil being adapted to facilitate rotational movement of theshaft across the abdominal wall. The proximal end of the shaft iscoupled to the trocar so that movement by the shaft across the abdominalwall is accompanied by movement of the trocar into the abdominal wall.

In an associated method, a trocar is placed across an abdominal wall ofa patient by providing a shaft in the form of a coil having a proximalend and a distal end. The proximal end of the coil is coupled to thetrocar so that screwing the coil into the abdominal wall moves thetrocar with the shaft into the abdominal wall with a mechanicaladvantage which is dependent upon the configuration of the coil.

In a further aspect, an anchor is adapted for use with a trocar having acannula configured for placement in an operative position across anabdominal wall. The anchor includes a coiled structural element whichextends outwardly of the cannula. This structural element has propertiesfor engaging the abdominal wall at a location spaced from the cannula toinhibit withdrawal of the cannula from its operative position.

Alternatively, the trocar can be removably coupled to the anchor by anexternal thread or helix which engages the coiled anchor. By screwingthe trocar into the anchor, a proximally directed force can be appliedto the trocar to elevate the abdominal wall while penetrating theabdominal wall.

These and other features and advantages of the invention will be betterunderstood with reference to certain preferred embodiments and theirassociated drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a patient in a prone position and prepared forlaparoscopic surgery;

FIG. 2 is a top plan view showing organs internal to an abdominal regionof the patient;

FIG. 3 is a side elevation view of the patient with an inflatedabdominal cavity;

FIG. 4 is a perspective view of an insufflation needle of the prior art;

FIG. 5 illustrates an initial step in an insertion method associatedwith the insufflation needles of the prior art;

FIG. 6 illustrates an undesirable puncture of internal organs which canresult when using the insufflation needles of the prior art;

FIG. 7 is a perspective view of one embodiment of the presentinsufflation device;

FIG. 8 is an enlarged perspective view of one embodiment of a distal endportion of the insufflation device illustrated in FIG. 7;

FIG. 9 is an enlarged perspective view of the distal end portion of analternate embodiment of the insufflation device;

FIG. 10 is a perspective view of an alternate embodiment of the deviceincluding a distal tip emitting visible light;

FIG. 11 is an enlarged perspective view of the distal end portion inanother embodiment of the insufflation device;

FIG. 12 is an enlarged perspective view of the distal end portion in afurther embodiment of the insufflation device;

FIG. 13 is an enlarged cross-section view of the abdominal wall showingan initial step in a preferred method for insertion of the device;

FIG. 14 is an enlarged cross-sectional view of the abdominal wallshowing a continuing step in a preferred method for insertion;

FIG. 15 is a close-up view of the abdominal wall illustrating a furtherstep in the insertion method as the distal end emerges in closeproximity to the internal organs of the patient;

FIG. 16 is a schematic perspective view of the device within theabdominal wall;

FIG. 17 is a perspective view of a wound site after removal of thedevice;

FIG. 18 is a front elevation view of a combination including aninsufflation device rotatably attached to a trocar;

FIG. 19 is a front elevation view showing the combination of FIG. 18 inuse to cross the abdominal wall;

FIGS. 20-26 illustrate a further embodiment of the invention;

FIG. 20 is a perspective view of the insufflation device or anchorassociated with this embodiment;

FIG. 21 is an assembled view showing an obturator inserted into acannula having an external helix;

FIG. 22 is a side elevation view of the trocar and anchor of thisembodiment;

FIG. 23 is a side elevation view showing engagement of the anchor by thetrocar;

FIG. 24 is a side elevation view of the trocar and anchor operablydisposed in a perpendicular relationship with a body wall;

FIG. 25 is a side elevation view of the trocar and anchor operablydisposed in an oblique relationship with the body wall; and

FIG. 26 illustrates proximal external forces applied to the trocar toelevate the abdominal wall, while distal internal forces are applied tothe trocar to penetrate the abdominal wall.

DESCRIPTION OF PREFERRED EMBODIMENTS AND BEST MODE OF THE INVENTION

A patient is illustrated in FIG. 1 and designated generally by thereference numeral 10. The patient 10 is shown in a prone position withhis abdomen 12 facing upwardly as he is readied for laparoscopicsurgery. In this process, minimally invasive surgery is undertakenthrough an abdominal wall 14 and within an abdominal region 16 of thepatient. This laparoscopic surgery commonly involves internal organs 18as best illustrated in FIG. 2. Rather than accessing these internalorgans 18 through a large opening in the abdominal wall 14, laparoscopicsurgery calls for minimal invasion of the abdominal wall 14 throughtubular access devices, commonly referred to as trocars. These trocarsare designated by the reference numeral 20 in FIG. 3.

The trocars 20 are placed through small openings in the abdominal wallto provide access for visualization and surgical instruments. They arecommonly provided with sharp points which although facilitating punctureof the abdominal wall, can be particularly threatening to the internalorgans 18 which initially are in close proximity to the abdominal wall.

It is for this reason that placement of the trocars 20 is commonlypreceded with inflation of the abdominal region in order to create anabdominal cavity 21. This initial step of inflating or insufflating theabdominal region 16 produces space between the abdominal wall 14 and theinternal organs 18 as best illustrated in FIG. 3. With this separationor space, placement of the trocars 20 is facilitated with a reducedthreat to the internal organs 18. Formation of the abdominal cavity 21also increases the size of the operative environment and enhancevisualization of the operative procedure.

Creation of the abdominal cavity 21 has typically been accomplishedusing an insufflation or Veress needle 23 as illustrated in FIG. 1. Thisneedle 23 has included an elongate cannula 25 having a distal end 27 anda proximal end 30. At the distal end 27, the cannula has been providedwith a sharp distal tip 31 of comparative interest to the presentinvention. At the proximal end 30, the cannula 25 has been coupledthrough a housing 32 to a connector 34. A source of gas under pressure36 has been coupled to the connector 34 to provide the insufflation gasthrough the cannula 25.

It is of particular importance to note that when the Veress needle 23 ofthe past is initially forced through the abdominal wall 14, there is noabdominal cavity 21. As a consequence, the internal organs 18 are notspaced from the abdominal wall 14, but are disposed closely adjacent tothe abdominal wall 14 as illustrated in FIG. 1. In order to avoidpuncture of these internal organs 18 by the sharp distal tip 31 of theinsufflation needle 23, a spring actuated safety member 38 has beenprovided as best illustrated in the enlarged view of FIG. 4.

Note that the present procedure for placement of the Veress needle hasgenerally required that the needle be inserted perpendicular to theabdominal wall 14. This has produced a perpendicular exit angle with aninner surface 39 of the abdominal wall 14, and most importantly hasproduced a highly detrimental perpendicular relationship between theVeress needle 23 and the interior organs 18.

In order to fully understand this critical moment when an access devicefirst emerges from the abdominal walls, reference is now made to FIG. 5which shows a greatly enlarged view of the abdominal wall 14 with theinternal organs 18 in close proximity. At the particular timeillustrated, the Veress needle 23 has been forced through the abdominalwall 14 and the sharp distal tip 31 has just become exposed at an innersurface 39 of the abdominal wall 14. With the intent of avoiding anydamage to the internal organs 18 by the sharp distal tip 31, the safetymember 38 has been deployed in this limited time and narrow space toshield the distal tip 31.

The mechanical requirements of this safety member deployment havelimited the timeliness of this protection with consequent damage to theinternal organs 18. While the safety member 38 reduces the probabilityof organ damage, the severity of this adverse occurrence remainssignificant. Furthermore, if a blood vessel is cut or an organpenetrated, the insufflation gas pressure will tend to inhibit anyleakage that might alert one to the damage. Under these circumstances,the procedure can be fully completed with the resulting damage becomingapparent only after the insufflation pressure has been relieved and theoperative site has been closed. This threatened exposure of the interiororgans 18 can also be seen in the wider view of FIG. 6.

It can be seen from FIGS. 5 and 6 that great care has been requiredduring insertion of the Veress needle 23 in order to avoid damage to theadjacent internal organs 18. The needle 23 is commonly inserted throughthe abdominal wall 14 by pushing forward or distally. The forward motionmust be carefully controlled to avoid overshooting the abdominal wall 14and inadvertently penetrating one of the internal organs 18 before thesafety member 38 can respond and move forward to shield the sharp tip31. This has required that the spring force be carefully balancedbetween that which is required to penetrate the abdominal wall 14 andthat which is required to prevent penetration of the internal organs 18.

As illustrated in FIG. 5, the abdominal wall 14 consists of skin 41,layers of muscle 43 and a layer of connective tissue 45. In addition,there is a final, internal membrane 47 referred to as the peritoneum.This membrane 47, which forms the inner surface 39 of the abdominal wall14, may be very thin and delicate or it may be very tough. In the lattercase, the safety member 38 associated with the distal end 27 of theVeress needle 23 may be unable to respond in sufficient time to beeffective, particularly if the peritoneum exerts an elastic load as theneedle 23 is urged forward. In short, an abrupt rupture of theperitoneum 47 may allow a sharp, unshielded tip to penetrate theinternal organs 18 before the safety member 38 can respond.

Referring to FIG. 7, a preferred embodiment of an insufflation device101 of the present invention is shown in the configuration of a coil 102formed of a spiraled length of hollow tubing 103. The coil 103 has adiameter 104, and an axis 105 extending between a proximal end 107 and adistal end 110.

At the distal end 110, a distal tip 111 can be rounded or blunted toensure that there are no sharp edges to cut or tear body tissue. Thedistal end 110 may have at least one side port 112 that permits gas toescape from the lumen of the tubing 103. The proximal end 107 of thecoil 102 may include a tubular extension 114 terminating in a connector116 which is adapted to be coupled to the source of gas 36 (FIG. 1). Thecoil 102 can be formed with individual convolutions 118 which are spacedto provide maximum engagement with the body tissue while avoidingovercompression and necrosis of the tissue.

With reference to FIG. 8, it will be appreciated that the distal end 110of the coiled insufflation device 101 can be substantially or completelyclosed and formed with a hemispherical distal tip 111 providing a smoothtransition to the coiled tubing 103. The side port 112 is preferablysized and configured to deliver maximum gas flow from the coiled tubing103 to the abdominal cavity 21.

In an alternate embodiment illustrated in FIG. 9, the distal tip 111 isformed from a material that is optically clear. This allows use of anoptical viewing device 121, such as an endoscope, angioscope or thelike. In such an embodiment, the optical viewing device 121 could bedisposed in the lumen of the coiled tubing 103 and subsequently advancedto the distal end 110 for visually monitoring insertion of theinsufflation device 101.

It will be noted by comparison, that in the past, insertion of theVeress needle 23 was a blind procedure which presented the greatestthreat to the internal organs 18 (FIG. 2). Only after the Veress needle23 had created the inflated abdominal cavity 21 and the first trocar 20was placed, could an endoscope be inserted to facilitate visualizationduring insertion of subsequent trocars. With the present device, thisvisualization is available to provide for safe placement of the accessdevice which initially crosses the abdominal wall 14.

In another embodiment illustrated in FIG. 10, the optical viewing device121 may include an illumination device or light 130 within the lumen ofthe coiled tubing 103. In this case, the light 130 will produce anilluminated area 132 that is viewable from outside the body of thepatient 10. This form of viewing, which is commonly referred to astransillumination, provides a clear indication as to the position of thedistal end 110 when it has reached a preferred location. The indicationmay be some change in the emission characteristics of the light 130, ormay result from diffusion of the omitted light in a manner thatindicates proper placement.

Referring now to FIGS. 11 and 12, the distal tip 111 of the coiledtubing 103 may present an end condition that is not rounded. Forinstance, the coil tubing 103 may terminate in a straight perpendicularsurface 125 as illustrated in FIG. 11. In this case, the lumen of thetubing 103 would be unobstructed.

In the embodiment of FIG. 12, the distal end 110 is provided with asharp, pointed tip 127. Although the preferred embodiment of the presentinvention comprises a blunt or rounded tip 111, the sharp tip 127 of theFIG. 12 embodiment still offers the significant advantage associatedwith the reduced entry and exit angles provided by the coilconstruction.

These entry and exit angles can be further appreciated with reference toFIGS. 13, 14, and 15 which show progressive positions of theinsufflation device 101 as it is maneuvered through the abdominal wall14. In FIG. 13, a nick 134 has been made in the skin 41 of the wall 14.By placing the axis 105 of the coil 102 at an angle to the abdominalwall 14, the entry angle of the distal tip 121 can be increased tofacilitate passage through the nick 134. In FIG. 13, this entry angle isdesignated by the Greek letter α. After the nick 134 has beenpenetrated, the coil 102 is preferably oriented so that its axis 105 issubstantially perpendicular to the abdominal wall 14 as illustrated inFIG. 14. This greatly reduces the entry angle α as the distal tip 121passes through the layer of muscle 43 and associated connective tissue45 (FIG. 5) which comprise the abdominal wall 14.

Continued penetration of the coiled tubing 103 through the abdominalwall 14 is illustrated in FIG. 14. As the coil 102 passes through theabdominal wall 14, as illustrated in the enlarged view of FIG. 15, thedistal tip and the following convolutions 118 exit the wall 14 at anexit angle designated by the Greek letter β in FIG. 15.

It is this exit angle β which is of particular importance to the presentinvention. Although this angle is measured with respect to an innersurface 136 of the abdominal wall 14, it can be appreciated that theinternal organs 18 are also in contact with, or generally parallel tothis inner surface 136. Accordingly, the exit angle β is also the anglewhich the distal tip 121 presents to the internal organs 18. When thisangle is generally perpendicular, as in the past (see FIG. 6), theprobability of organ penetration is great. However, when this exit angleβ is reduced to a very small acute angle, the distal tip 111 tends toslide along the surface of the internal organs 18, particularly if thedistal tip 111 has a blunt configuration as first discussed withreference to FIG. 8.

In FIG. 16, the coiled device 101 of the present invention isillustrated schematically so that one can appreciate the forcesassociated with placement of the device 101 through the body wall 14. Inthe past, the straight Veress needle 23 (FIG. 1) would be placed using aforce applied in the same direction as that desired for movement of thedevice 101, specifically a forward force applied in the directionrepresented by an arrow 150. Note that the insufflation device 101 ofthe present embodiment moves in the desired forward direction 150, butdoes so only in response to a rotational force represented by an arrow152. The forward direction of movement illustrated by the arrow 150, mayeven be realized while the coiled tubing 103 is pulled backwardly by aforce opposite to the forward direction of arrow 150. In other words,once the distal tip 111 is adequately engaged within the abdominal wall14, FIG. 13, preferably within a small skin incision or nick 134 (FIG.13), the entire device 101 may be held in traction rather than pushed toprovide the desired forward motion. The coiled tubing 103 acts as a“corkscrew” and propels or advances itself in the forward direction 150,but only in response to rotational motion shown by arrow 152. Thistractional rotation of the coiled tubing 103 tends to provide a safetymargin as the body wall 14 is pulled or drawn away from the internalorgans 18.

With further reference to FIG. 7, it can be seen that the presentinvention may comprise larger than ordinary tubing 103 since theplacement force is not perpendicular to the abdominal wall 14 andinternal organs 18. In fact, the placement force, as shown by arrow 152,is rotational and incremental rather than direct and uncontrollable. Inaddition, the slow and deliberate advancement of the blunt distal end110 gradually parts tissue, such as the skin 41, muscle 43, andconnective tissue 45 in a more natural manner than with the straight,cutting penetration of the past. The blunt distal end 110 tends to windits way through body tissue seeking weak, less dense or fatty tissue,and avoiding included blood vessels, and muscle that is normally morevascular than fatty tissue.

An insertion site 21 associated with the present invention is shown inFIG. 17 at a time when the device 101 has been removed, and the tissue,previously separated by the procedure, has generally returned to itsoriginal condition. Since little or no cutting has occurred, there isminimal bleeding and no potential for herniation of the site. A track154 through which the device 101 passes as it is rotated through thetissue, has the same length and convoluted nature as the device 101itself. With respect to the track 138, its length, convoluted nature andgeneral lack of cut tissue provides improved healing even though thediameter size of the insufflation device 101 may have been as much astwo or three times that of existing insufflation needles.

With further reference to this enlarged diameter, it will be noted thatthe insufflation device 101 can provide a gas flow significantly greaterthan existing insufflation needles. But even if the diameter or gaugesize of the present insufflation device 101 is the same as that of theprior art, its gas flow will be significantly greater primarily due tothe lack of obstruction in the lumen of the tubing 103.

Many of the advantages associated with the coiled insufflation device101 can be further appreciated in combination with a trocar, such as thetrocar 20 discussed with reference to FIG. 3. In this combination,illustrated in FIG. 18, the trocar 20 is shown to have a valve housing141, a cannula 143, and a removable obturator 145. The coiledinsufflation device 101 is rotatably attached to the trocar 20, forexample with an attachment ring 147.

The trocar 20 is preferably disposed inside of and coaxial with thecoiled insufflation device 101. With this orientation, the device 101 isfree to rotate on its axis around the cannula 143 of the trocar 20. Thedevice 101 will typically be as long as, if not slightly longer than,the cannula 143 so that the distal tip 111 extends at least to the tipof the obturator 145.

Operation of this combination is illustrated in FIG. 19. As the coiledinsufflation device 101 is rotated into the abdominal wall 14 of thepatient, it advances in the manner previously discussed. Due to itsattachment to the trocar 20, this advancement tends to pull the trocarinto the abdominal wall 14. One major advantage associated with thiscombination is that the device 101 provides an outward counter forcewhich resists any tendency of the abdominal wall 14 to tent inwardly dueto the forward movement of the trocar 20.

This system would be particularly useful for bariatric patients whichhave a large quantity of abdominal wall fat. In these patients, often alarge amount of leverage must be applied against the trocar to overcomethe bulk of abdominal wall fat. This in turn widens the trocar entrywound and makes slippage of the trocar more likely. With the combinationof the trocar 20 and insufflation device 101, the surgeon does not haveto fight the abdominal wall during insertion and will further benefitfrom the tremendous retention provided by the insufflation device 101.

A further advantage associated with this combination can be appreciatedby noting that trocars are typically placed normal to the surface of theabdominal wall 14 and also normal to the peritoneum. In the past, aninwardly directed force was applied to the trocar 20 to push the trocar20 through the abdominal wall 14. This force caused the abdominal wallto tent inwardly as the force was directed against succeeding muscularand fat layers of the wall 14. Ultimately, the force was directedagainst the peritoneum.

With the present combination, the device 101 can be pulled with anoutwardly directed force while the trocar 20 is pushed with an inwardlydirected force. When the outward force exceeds the inward force, twosignificant advantages are realized. First, there is no inward tenting:Second, the abdominal wall is elevated creating an abdominal cavityseparating the abdominal wall from the internal organs. Creation of thiscavity greatly reduces any risk of damage to the organs when wall 14 isfinally penetrated by the trocar 20.

Not withstanding these significant features, the device 101 provides afurther advantage as it functions to hold the peritoneum against theremainder of the abdominal wall 14. This feature resists any tendencytoward peritoneal separation regardless of its cause. For the firsttime, angular placement of the trocar 20 can be accommodated without arisk of separating the peritoneum from the adjacent layer of theabdominal wall 14. Angular placement will also enable the surgeon toreach lateral internal sites more easily, without forcing the trocar 20to cant with commensurate stress on the instruments.

A further embodiment of the invention is illustrated in FIGS. 21-24.This embodiment is similar to that of FIG. 18 in that it includes theinsufflation device 101 (FIG. 20), the trocar 20 with cannula 143 (FIG.21), and the obturator 145 (FIG. 21).

However, the embodiment of FIG. 21 differs from that of FIG. 18 in atleast two aspects. First, the insufflation device 101 is not attached tothe trocar, but rather is separate from the trocar to permit the uniqueoperation discussed in greater detail below. Second, a helix 161 isformed on the outer surface of the cannula 143 of the trocar 20. Thishelix 161 can be formed with multiple convolutions or preferrably withonly a single convolution 163. In this embodiment, the helix 161functions as an external thread 165 on the trocar 20. Its preferredplacement could be anywhere along the cannula 143, or perhaps even onthe exposed distal tip of the obturator 145.

Referring now to FIG. 22, it can be seen that the insufflation device101 can function in this embodiment as an anchor 167 which can beembedded in the abdominal wall 14 in the manner previously discussed. Inthis operative position, the anchor 167 can function as an insufflationneedle; however, in this case the anchor 167 has an additional purposeand that is to provide the helix or coil 102 which can function as aninternal thread.

With the anchor 167 functioning as an internal thread and the helix 161functioning as an external thread, it can be seen that the helix 161 canactually be screwed into the anchor 167 as a bolt would be screwed intoa nut. This relationship is best illustrated in FIG. 23.

Once the anchor 167 is screwed into the abdominal wall 14 as illustratedin FIG. 24, the trocar 20 with its external thread or helix 161 can bescrewed into the anchor 167 thereby drawing the trocar 20 through theabdominal wall 14. As the helix 161 is screwed into the anchor 167, aninternal force is developed between these two structures which moves thetrocar 20 forward or distally into the abdominal wall 14. No directionalexternal force is required to produce this forward movement. The usermerely rotates the trocar 20 as shown by the arrows 169, to produce theinternal force that draws the trocar 20 into the abdominal wall 14.

The system and method associated with this embodiment is particularlybeneficial when the trocar 20 is to be inserted at a non-perpendicularangle to the abdominal wall 14. For example, in FIG. 25, the trocar 20is to be inserted at an angle to the abdominal wall 14. With trocars ofthe past, this would ultimately bring the distal trip of the obturatorinto an angular relationship with the peritoneum 171 of the abdominalwall 14. Since the peritoneum 171 forms a relatively strong innersurface of the wall 14, an angular relationship with the trocars of thepast has tended to resist penetration of the peritoneum 171 andultimately separated the peritoneum 171 from the remainder of the wall14.

With the present embodiment, the anchor 167 is initially placed at thepreferred angle, as illustrated in FIG. 25. Then the trocar 20 is merelythreaded along the axis of the anchor 167. In this case, the anchor 167defines the pathway through the peritoneum 171 and provides a continuousaxial force which draws the trocar 20 along the axis of the anchor 167.In this manner, an angular placement of the trocar 20 can be easilyachieved without substantial risk of peritoneal separation.

In this embodiment, the anchor 167 can function as an insufflationneedle as discussed with reference to previous embodiments. However,certainly one of its primary functions is to helically receive thetrocar 20 even while it is being inserted. Once the trocar 20 engagesthe anchor 167, a rearward or proximate force can be applied to thetrocar 20 to elevate the abdominal wall 14 and thereby create theabdominal cavity 21. This external force would typically be appliedalong the arrow 173 as illustrated in FIG. 24.

It is now interesting to contemplate the external forces applied by theuser, in combination with the internal forces developed between thetrocar 20 and anchor 167. In operation, the anchor 167 is initiallyinserted into the abdominal wall 14 in the manner previously discussed.Then the user moves the cannula 143 of the trocar 20 along the axis ofthe anchor 167 until the external thread or helix 161 engages theinternal thread or coil 102 of the anchor 167. The user can then merelyturn the trocar in the direction of the arrows 167 to provide anengagement between the helix 161 and coil 102. Once this engagement isachieved, the user can pull the trocar 20 proximally along the arrow 173to elevate the abdominal wall 14 and produce the abdominal cavity 21.Continued turning of the trocar 20 will produce the internal forcebetween the helix 161 and coil 102 which draws the trocar 20 distallyinto the elevated abdominal wall 14. When the peritoneum 171 ispenetrated, the distal tip of the obturator 145 moves into the abdominalcavity 121 with a substantially reduced risk to the internal organs 18.

It will be understood that many other modifications can be made to thevarious disclosed embodiments without departing from the spirit andscope of the concept. For example, various sizes of the surgical deviceare contemplated as well as various types of constructions andmaterials. It will also be apparent that many modifications can be madeto the configuration of parts as well as their interaction. For thesereasons, the above description should not be construed as limiting theinvention, but should be interpreted as merely exemplary of preferredembodiments. Those skilled in the art will envision other modificationswithin the scope and spirit of the present invention as defined by thefollowing claims.

1. A system for providing access across a body wall, the system comprising: a length of tubing having a proximal end, a distal end and a tubing lumen having a proximal opening and a distal opening; the overall length of the tubing defining a longitudinal axis and the tubing lumen defining a lumen axis; a clear distal tip connected to and closing the distal opening of the tubing; the clear distal tip being adapted to penetrate tissue and provide optical viewing through the distal tip; wherein the lumen axis at the distal end of the tubing is angled with respect to the longitudinal axis such that optical viewing through the clear distal tip is generally along the lumen axis and angled with respect to the longitudinal axis.
 2. The system of claim 1 further including an optical element disposed inside the lumen of the tubing and located at the distal end for visually monitoring through the clear distal tip at an angle to the longitudinal axis.
 3. The system of claim 2 wherein the optical element includes an illumination device.
 4. The system of claim 1 wherein the length of tubing is configured into a coil shape.
 5. The system of claim 1 wherein the proximal opening is connected to a source of fluid under pressure and the distal end includes at least one port formed in the tubing adjacent to the distal opening; the at least one port being adapted to expel the fluid under pressure.
 6. The system of claim 1 wherein the distal tip is blunt.
 7. The system of claim 1 further including a trocar comprising an elongated shaft having a proximal end and a distal end defining a longitudinal axis and a lumen; the trocar being disposed inside of the tubing such that the longitudinal axis of the tubing is co-axial with the longitudinal axis of the trocar.
 8. The system of claim 7 wherein the distal end includes at least one port adjacent to the distal opening.
 9. The system of claim 7 wherein the tubing is coiled around the outside of the trocar.
 10. The system of claim 7 further including a removable obturator inside the lumen of the trocar.
 11. A system for providing access across a body wall, the system comprising: a length of tubing having a proximal end, a distal end and a tubing lumen having a proximal opening and a distal opening; the overall length of the tubing defining a longitudinal axis and the tubing lumen defining a lumen axis; a clear distal tip connected to and closing the distal opening of the tubing; the clear distal tip being adapted to penetrate tissue and provide optical viewing through the distal tip; and an optical element at the distal end for visualization through the clear distal tip at an angle to the longitudinal axis.
 12. A system for providing access across a body wall, the system comprising: a trocar comprising a cannula having a lumen; a length of tubing having a proximal end and a distal end adapted to penetrate tissue; the length of the tubing defining a longitudinal axis and coaxially surrounding the cannula; an obturator comprising an elongated shaft with a blunt distal end and longitudinal axis; the obturator being coaxially disposed within the cannula; wherein the distal end of the tubing extends slightly beyond the obturator and movement of the tubing is accompanied by movement of the obturator such that the penetrating distal end of the tubing leads the blunt distal end of the obturator through the body wall.
 13. The system of claim 12 wherein the tubing is configured in the shape of a coil.
 14. The system of claim 12 wherein movement of the tubing pulls the obturator through the body wall.
 15. The system of claim 12 wherein the tubing is configured in the shape of a coil and rotational movement of the tubing pulls the obturator through the body wall.
 16. The system of claim 12 wherein the tubing is rotatable relative to the cannula.
 17. The system of claim 12 wherein the tubing is connected to the trocar such that longitudinal movement of the tubing is fixed and the tubing is rotatable relative to the trocar.
 18. The system of claim 12 wherein the distal end of the tubing has a sharp pointed tip.
 19. A system for providing access across a body wall, the system comprising: a length of tubing having a proximal end, a distal end and a tubing lumen having a proximal opening and a distal opening; the overall length of the tubing defining a longitudinal axis and the tubing lumen defining a lumen axis; a distal tip connected to the distal opening of the tubing; the distal tip being adapted to penetrate tissue; wherein the distal tip has a distal end that is angled with respect to the lumen axis such that the most distal point of the distal end is offset from the lumen axis; at least a portion of the distal tip has a progressively decreasing cross-sectional area taken perpendicular to the lumen axis with distance toward the most distal point; and the distal end of the distal tip defining an angled opening to provide optical viewing through the angled opening.
 20. The system of claim 19 wherein the distal tip is curved. 